Table saws are well known machines for cutting and forming kerfs in wood and other materials. In such devices material is fed to a power driven saw wheel, or vice versa. Because the type of material being cut, its thickness, and other factors can vary, a wide variety of saw wheels having different characteristics are in use. One problem with such saws has been the need to change saw wheels when the type of material to be cut is changed. One prior solution has been to unbolt the saw wheel from its spindle, replacing it with a suitable saw wheel for the task at hand. Such a procedure is cumbersome, requires the use of hand tools, and can be particularly awkward for a table saw, in which the operator is required to work beneath the saw table to reach the hub of the saw wheel. This is not a satisfactory solution to the problem.
Others have tried to produce a saw in which blades can be changed without disconnecting a particular saw wheel. Some such saws have employed a rotatable turret beneath the saw table which can be indexed to present a particular blade through the slot of the table. But the prior art devices have disadvantages. In some such devices each saw wheel has its own motor, eliminating the need to disconnect and reconnect a motor each time a saw wheel is changed, but requiring as many motors as saw wheels, which adds considerably to the expense of the machine. Furthermore, since each motor must have power fed to it, either commutators must be provided or the dress of the line cord which feeds power to the components mounted on the turret limits the turret's freedom to turn.
Another solution to the problem has been to provide a table saw with a single drive which drives every saw wheel on the turret, including the ones not in use. Although such a device has only one motor and requires no clutches or the like, it has the disadvantage of being unsafe, since several saw wheels are moving at once.
Another disadvantage in some prior art multiple saw wheel designs is the inability to adjust blade height and inclination.